Samsung, which was undoubtedly surprised by the usually-slow-to-market Apple announcing that the iPhone 5S would be the first 64-bit smartphone on the market, has announced that its “next smartphones” will also have “64-bit processing functionality.”
This presumably means that the Galaxy S5, or perhaps the phone after that, will have a 64-bit SoC – and, perhaps more importantly, that Android will make the leap to 64-bit, too. Whether smartphones actually gain anything from 64-bit processing, or whether this is merely a 3DTV-like marketing ploy, is another question entirely.
At the iPhone 5S launch last week, Apple surprised us all by announcing that its new smartphone would be the first in the world to support 64-bit software. In true Apple style, we don’t know a whole lot about the A7, except that it’s Apple-designed and based on the new ARMv8 instruction set. ARMv8 is 64-bit, but it is backwards compatible with 32-bit ARMv7.
Almost every mobile chip in the last few years has been based on the ARMv7 Cortex-A7 or A9 cores, with the exception of Qualcomm and Apple, who designed their own cores (which are still fairly similar to ARM’s reference cores). While there is a Cortex-A15, its large power envelope makes it almost unusable in smartphones – and then there’s Cortex-A53 and A57, which are ARM’s first 64-bit reference designs.
As far as we can tell, judging by the limited info released by Apple, the A7 SoC is probably based on the Cortex-A57 core. Samsung, when it releases a 64-bit phone, will almost certainly use an Exynos SoC that uses the Cortex-A57 CPU core. This is all well and good, except for one thing: Cortex-A57, ARMv8, and 64-bit computing are essentially useless in mobile devices. They are primarily low power, high density server-oriented technologies.
There is almost no reason for Samsung to follow in the A7’s footsteps, except to counter any marketing FUD that Apple throws up. There are minimal performance gains to be had from switching to 64-bit, and in some cases there might even be a small hit to performance and battery life. You might see this as long-term future proofing, but even on desktop PCs, where x86-64 chips have been the norm for 10 years, the impact of 64-bit computing has been negligible. Yes, we need to switch to 64-bit at some point, but there are probably more important things that Apple, Samsung, and other mobile device makers should be focusing on at the moment.
And then there’s Android. As it stands, Android is completely 32-bit, and if a lot of work is being done on 64-bit, it certainly isn’t being done publicly. I would be extremely surprised if Android 4.4 KitKat turns out to be a 64-bit OS. Porting Android to 64-bit would be a fairly large undertaking, and I doubt that Google would invest the time and effort unless there was a valid reason to do so. In this regard, it will probably come down to how loudly Apple beats the 64-bit drum; if Apple can somehow get the public to think that 64 bits are better than 32 (which wouldn’t be hard), then Google will have no choice but to make the jump.
It’s also worth noting that Google is the largest operator of computer servers in the world, and is thus probably very interested in low power ARM servers. Google’s internal server setup is shrouded in secrecy, but it’s probably safe to assume that it has at least dabbled in ultra-high-density ARM servers – and that is an area where 64-bit processing makes a lot of sense. There is possibly some crossover between Google’s server work and 64-bit Android.
While we're on the subject of 64-bit smartphones, you might also want to check out: What's the point of a 64-bit iPhone 5S? Look to the iPad and Mac.